Electrical contact and method of operating same



Feb. 13, 1923.

R. F. BRACKE. ELECTRICAL CONTACT AND METHOD OF OPERATING SAME. men MAXI! 1919.

Irv/97%" Patented Feb. 13, 1923.

UNITED STATES PATENT OFFICE.

ROBERT F. BRACKE, OF CHICAGO, ILIiINOIS, ASSIGNOR OF ONE-HALF TO CHARLES L. STOKES, 01" LOS ANGELES, CALIFORNIA.

ELECTRICAL CONTACT AND METHOD OF OPERATING SAME.

Application filed Kay 8, 1919. Serial No. 295,616.

To all to ham it may concern Be it known that I, ROBERT F. BRACKE, a citizen of the United States, residing at hicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Electrical Contact and Methods of Operating Same, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to contact mechanism and method of operating said mechanism to open and close an electric circuit.

Broadly, the objects of the present inven tion reside in the provision of contact mechanism in which the time interval of contact is constant regardless of the speed of operation of the controlling element, and in which the contacts are never permanently closed even though the operation of the controlling element be discontinued.

Further objects reside in providing agood wiping, and a quick make and break contact mechanism.

These and other objects of the present invention will be pointed out in detail in connection with the accompanying drawings, in which-- Figure 1 is a diagrammatic view of one form of contact mechanism constructed and operated in accordance with my invention;

v to rotate the lever in a clockwise direction- Figure 2 is a detailed view of an interrupter provided with the contact mechanism carried by a lever 9, pivoted at 10 to any suitable support. A spring 11 is interposed between the lever 9 and a support, and tends in this figure. Carried by the lever 9 and extending under the fiat spring 6 is a lug 12, whichis insulated from the lever 9 car'- rying the contact 8. If desired this lug may be made pf insulating material, as shown in the drawings.

Co-operating with the under side of the lever 9 is a cam 13 mounted on a shaft 14. The shaft 14 is arranged to be driven by the device with which the contact mechanism is combustion engines, or in connection with any form of mechanism in which an electric circuit is opened and closed. In Figure 1 I have shown an electric circuit at 15, in cluding the spring 6, the contacts 7 and 8, lever 9, battery 16, and translating device 17. The translating device may be anything arranged to operate upon the passage of a current therethrough, as for example a recording or printing device.

The operation of the mechanism shown in Figure 1 is as follows:

The cam 13, mounted on the shaft 14, is rotated in a clockwise direction, and as the cam moves from under the lever 9, the spring 11 is permitted to move'the lever downwardly, causing engagement between the contacts 7 and 8. As the lever 9 con tinues in its downward movement, the spring 6 which carries the contact 7 is moved downwardly past the dead center line-a,

causing the spring 6 to snap into the position shown in dotted lines. and thereby producing separation of the contacts 7 and 8. As the cam 13 continues to rotate, the lever 9 is gradually moved upwardly, causing the insulated lug 12 to engage the under side of the spring 6 and move the spring upv wardly past the dead center line. When the spring in its upward movement passes the dead center line, it snaps to the position shown in full lines, but the contacts 7 and 8 do not engage at this time, for the reason that the contact 8 has been moved upwardly. far enough to prevent such engagement. the cam 13 continues to rotate, the operation above described is repeated. It will be seen from the description thus far given that under a certain maximum speed the length of time during which the contacts 7 and 8 are in engagement is constant, regardless of the speed of the operating element 14. Attention is also directed to the factth t an. exceptionally good wiping. contact 1s made by the contact 8'when it is moved downwardly to force the spring 6 beyond the dead center line,

1 spring element 6. The plate 18 carries the" In Figure 2 I have shown the mechanism just described applied to an interrupter for use in connection with an internal combustion engine ignition circuit. In this figure,

18 designates a rotating plate carrying the engaged by the cams 20 and 21, the returnof the lever 9' to its original position being accomplished by the spring 23.

'mounted on the lever 9 In Figure 3 I have shown'diagrammatically what is probably the preferred form of 'my invention. In the arrangement here shown, I provide a coil spring 24, which takes the place of the flat springs 6 and 6- I in the other devices. The coil spring 24 is fixed at 25 to a support, and is attached at its opposite end 26 to a lever 27, pivoted at 28 vto-a suitable support. The tendency of the spring 2 1 is to move the lever 27 awa' from the dead center-"line shown at I). he lever 27 carries a. contact 7", adapted to co-operate with the contact 8' of the lever 27 is adapted to. be engaged and lifted by the insulated lug 12". Movementof the lever 27 in a counter clockwise direction in this figure is limited by a stop 1 29. The operation of the device just'described is identical with that described in connection with Figure 1. When the lever 9" is permitted-to move downwardly, the contacts 7 and 8". come into engagement, and the lever 27 is moved downwardly past the dead center line b. The spring 26 is thus moved below the pivot 28, with the result that the lever 27 is moved suddenly in a clockwise direction against the lug 12", and the contacts 7 and 8" are separated.

' As the cam associated with the lever 9" Attention'is directed to the fact that at continues its rotation, the several parts are returned to their original positions, with the contacts separated.

no time is it possible to move the contacts 7 and 8 into engagement and to keep them in such engagement for 'an indefinite length oftimeu If the rotation-of the shaft 14 is discontinued immediately after the lever 9 is released, the contacts 7 and 8 are permitted to close but are also separated by the continued downward movement of the lever 9.

forms a bell.

The under side a pair of normally separated contacts,.

means for moving one of said contacts into engagement with the other of said contacts, and spring means actuated by the firstmentioned contact for moving the lastmentioned contact away from the first.

3. Electric contact mechanism comprising" a lever, a contact mounted thereon,

spring means associated with said lever for moving the lever either way from a dead center line, and a' second cont-act adapted for engagement with the first contact and for moving the first contact and lever beyond the dead center line.

4. -Electric contact mechanism comprising a lever, a contact mounted thereon, spring means associated with said lever for moving the lever .either way from a dead center line, a second contact adapted for engagement with the'first contact and for moving the first contact and lever beyond the dead center line, and mechanism for returning the contacts separated to their original positions.

5. Electric ing a lever, 21. -contact mounted thereon, spring means associated with said lever for moving the lever either way from a dead center line, a second lever and contact mounted thereon, spring means tending to move the second lever and contact toward the first contact and for moving the first contact mechanism compriscontact and lever. beyond the dead center 'thereon, spring means tending to move the second lever and contact toward the first contact and for moving the first contact and lever beyond the dead center line, cam mechanism for releasing the said second lever, and means for returning the levers with the contacts separated to their original I positions. V

In witness whereof, I hereunto subscribe my name. this 2nd 'dav-of Mayf19l9.

v ROBERT F. BRACKE. Witnesses f MARY PETRIE, EDNA V. YGUSTAISON, 

